54 BRITISH CRETACEOUS BRACHIOPODA. 



distinguishes it from T. semiglobosa, and I therefore cannot agree with Professors Bronn, 1 

 Reuss, 2 and V. Buch, 3 who place it as a synonym of that species. M. D'Orbigny 

 considers T. Albensis* a synonym of Obesa, but I am more inclined to place it as a 

 variety of Semiglobosa. T. sulcifera, Morris, 5 in my opinion more closely approaches 

 T. obesa than any of the others mentioned, but from the remarkable, regular, and peculiar 

 concentric lines of growth ornamenting its surface it may be conveniently retained under 

 a distinct appellation. The largest specimen of T. obesa, yet discovered, is from the 

 Upper Green Sand ; but almost as large a shell has likewise been obtained from the 

 Chalk in the neighbourhood of Norwich. Sowerby states his specimens to be from 

 the Chalk at Norton Bevant, near Warminster. In France it is rare at Rouen, and 

 indeed everywhere, although common in the state of T. Dutempliana, which seems to con- 

 firm my views above mentioned. On the sides of the valve may be remarked small raised 

 strise ; this is also observable on T. Dutempliana. 



Plate V, fig. ] 3, 14. The two largest known specimens, from the Chalk of Norwich, 



in the collection of Mr. Fitch. 

 „ fig. 15. A specimen from the same locality, in my collection, much resembling 



Sowerby's figure in the ' Min. Conch.' 

 „ fig. 16. The largest specimen yet discovered of this species, from the 

 Upper Green Sand, near Warminster, in the collection of Mr. 

 Cunnington. 



1 Index Pal., p. 1250, Prof. Bronn mentions as synonyms of T. semiglobosa, T. subundata, undata, 

 obesa, and albensis, none of which we believe correctly placed with T. obesa. 



2 Die Vers, der Bohem. Kreid., 1846, p. 51. The following are the synonyms here given of 

 T. semiglobosa, T. intermedia, (a cornbrash shell,) T. albensis, T. subundata, T. obesa, T. acuta, none of 

 Reuss' figures resemble Sowerby's T. obesa. 



3 Uber Ter. and Mem. de la Soc. Geol. de France, vol. iii, p. 225. V. Buch's synonyms are still 

 more defective; he considers T. globata, Sow., an inferior oolite shell, and T. Sphceroidalis, likewise from 

 the same strata, as synonyms of T. obesa, this last with a point of interrogation. 



* Leymerie Mem. de la Soc. Geol. de France, vol. xv, p. 11, pi. v, figs. 1 — 3. 



5 Morris and Dav. 'Ann. and Mag. of Nat. Hist.,' vol. xx, p. 254, pi. xviii, figs. 7, 7*. 1847. 



